A person seeking salvation, enlightened by faith, must have a thorough knowledge of what the Christian faith requires of him, how he should live and act as a Christian, for, not knowing the foundations of faith, he cannot determine for himself what and why he believes, cannot adequately prepare and receive the Sacraments, participate in the life of the Church. This book contains simple and complex questions, the answers to which reflect the essence of Orthodoxy. St. Demetrius of Rostov sets out in completeness and mutual connection the foundations of faith and morality for each Christian.